DiCaprio, who just broke up with Victoria's Secret supermodel Erin Heatherton, and stunning blonde Australian actress Robbie, who plays Leo's love interest Naomi Lapaglia in the Martin Scorsese-directed movie, appeared close at the party at the Wynn Las Vegas on Saturday night.

One witness said, "There looks to be some strong chemistry between Leo and his leading lady. They spent a lot of time at the party together."

How gentlemanly by Leo to give Margot a chance even though she hasn't walked down a runway in her life. Maybe if Margot gets real lucky, Leo will let her give him a blowjob on the first date. *fingers crossed*